<div
  class="ui-grid-row-header-cell ui-grid-expandable-buttons-cell">
  <div
    class="ui-grid-cell-contents">
    <i
      ng-class="{ 'ui-grid-icon-plus-squared' : !row.isExpanded, 'ui-grid-icon-minus-squared' : row.isExpanded }"
      ng-click="grid.api.expandable.toggleRowExpansion(row.entity)">
    </i>
  </div>
</div>
